Craig Childs walks with desert ghosts on the Navajo Nation

The dogs are getting closer, barking through junipers about a half-mile away. We douse our small can stove, scoop the rest of breakfast into our mouths, and within two minutes are gone.

The day before, we were dropped off on a dirt two-track where we hopped a gate and smuggled ourselves into the wilderness atop this humpback mesa, 10 days of gear on our backs. We don't want to encounter men, women, dogs, trails, anything. Just raw earth and nowhere.

The man with me calls himself a ghost walker. Not to be confused, he insists, with skinwalkers, Navajo witches. Rather, he walks making as few tracks as possible. Sometimes barefoot, sometimes wearing sandals made out of yucca strips, he's hiked hundreds of miles through the Southwest, hiding out at edges of towns. His real name is Colin. A tall man with broad shoulders, and his thrift-store clothing never fits quite right. He's nearing the end of his 20s, wears a greasy hat and a big knife on his hip. Intimidating if you don't know his palms sweat when he meets girls.

We had set out to cross the Navajo Reservation over a swath of canyon-riddled mesas in far northern Arizona. It's off-limits, but a young Navajo man smoking weed out of a Coke can in the front of his truck had told us you can walk anywhere across those mesas -- as long as nobody sees you.

We quickly leave the dogs behind, taking the first exit up a steep ravine. Hand over hand, we rise a few hundred feet along the side of a rimrock mesa, ice pocketed between tipped and tenuous boulders. From the edge, the high desert spreads as far as we can see, the town of Kayenta glimmering in the distance like broken glass. We don't break the horizon for long, slipping quickly into bedrock canyons beyond. Ghost-walking. Colin grins. I grin, too. Disappearing is our favorite pastime.

At a crux descent -- rock walls steepened into a cliff and a crack -- we find fat juniper-posts notched into the rock as a staircase; it looks as if it has not been used for centuries, each step splintered, too fragile to hold our weight. We climb around, wondering at the early Navajo who built it, perhaps in the days of first Spanish arrival, back when this was a different land, no pavement, no United States of America. It's not the first human sign that we've found, nor the last.

Farther inside the web of canyons, crumbled cliff dwellings appear -- ancient villages that predate any archaeological record of the Navajo. The ruins are wedged into rock-fractures and perched on ledges, dark-windowed towers like castle turrets over our heads. They are of Pueblo origin. Navajo call those who built them Anasazi -- Other. When the Navajo arrived here sometime around the 16th century, they were nomads traveling from the north. They would have found an embattled, post-abandonment landscape where the Pueblo world had just gone through one of its legendary meltdowns. The landscape had been swept by drought and conflict -- caves full of corpses, withered human heads in cliff-dwelling doorways and windows, human bones stirred in cooking pots and cast aside. No wonder the people who live here talk about skinwalkers. I've heard stories of witches and corpse-diggers. A Mormon who lived in this area once told me coyotes walking around on two legs came banging on his door. He shot one; a Navajo woman was found dead the next day.

We pull off our boots and move barefoot below the ruins, negotiating scads of old snow, splintered ceiling-wood and brightly colored potsherds. Partly we walk this way for the benefit of future visitors, lightening the weight of our step so it will still appear as if nobody has visited these sites in a very long time, a nod to the language and spirit of the 1964 Wilderness Act. Mostly, though, we move barefoot so as not to stir the ghosts.

I pause at a half-buried bone, perhaps human. It has rolled down with everything else from a collapsing structure. I almost touch it, but do not. My heart beats quicker than it should. Traditional Navajos say, Don't do it; around here, death will leap right into your soul.